Drug Interactions

药物相互作用

• 批准号: 8118442
• 负责人: Allan Edward Rettie
• 金额: $ 44.05万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/8118442
• 关键词: ATP Hydrolysis; Ablation; Behavior; Binding; Binding Sites; Blood - brain barrier anatomy; Brain; CYP3A4 gene; Categories; Cell model; Cells; Chemicals; Cyclosporine; Data; Development; Drug Binding Site; Drug Combinations; Drug Interactions; Drug toxicity; Exhibits; Fluorescence; Fluorescent Dyes; Funding; Genes; Genetic; Goals; HIV Protease Inhibitors; Human; In Vitro; Ketoconazole; Knock-out; Knockout Mice; Laboratories; Ligand Binding; Ligands; Measures; Methods; Modeling; Monitor; Multi-Drug Resistance; Mus; Nature; Neuraxis; P-Glycoprotein; P-Glycoproteins; Pharmaceutical Preparations; Plasma; Play; Positron-Emission Tomography; Quinidine; Quinine; Rattus; Rodent; Role; Techniques; Testing; Therapeutic; Time; Verapamil; Wild Type Mouse; base; design; drug distribution; imaging modality; in vivo; inhibitor/antagonist; innovation; mouse model; novel; tomography; vector control

Genetic or chemical knock-out of P-glycoprotein (P-gp; MDR1) at the rodent blood-brain barrier (BBB) significantly increases (by 10 to 30-fold) the distribution of P-gp substrate drugs into the brain. Based on these data, it has been widely postulated that P-gp plays a vital role in limiting drug distribution at the human BBB and that P-gp based drug interactions at the human BBB are likely to be profound. Our hypothesis challenges this well-established paradigm and claims that such interactions will be modest because therapeutic plasma concentrations of potential P-gp inhibitor drugs will be insufficient to profoundly inhibit Pgp at the human BBB. Moreover, we hypothesize that such drug interactions can be quantitatively predicted by in vitro cell models and in vivo studies in the rat. The development by our laboratory of a novel and innovative non-invasive, Positron Emission Tomography (PET) imaging method to measure P-gp activity at the human BBB will allow us to test these hypotheses. Since P-gp can demonstrate allosteric activation and multiple binding sites, predictions of P-gp based drug interactions can be complicated by these phenomena. Therefore, our specific aims will be: 1. In vitro studies: We will determine the potency of a variety of drugs (EC50) to inhibit P-gp efflux of verapamil-bodipy by LLCPK1 cells expressing the MDR1 gene or an empty vector (control cells). 2. In vivo rodent studies: For the drugs studied (aim 1), we will determine the ratio of the therapeutic maximum plasma concentration (Cmax) and EC50 (Cmax/ECso) as well as the unbound maximum plasma concentration (Cmaxu) and EC5o(Cmaxu/EC5o). For those drugs (n=4) that are potent inhibitors of P-gp at their therapeutic concentrations (highest ratios), we will determine their in vivo EC50 at the rat BBB using [3H]-verapamil as the P-gp substrate. In vivo human studies: The two most potent inhibitors identified from the rat studies will be tested (at Cmax) for their ability to inhibit P-gp activity at the human BBB by measuring, using PET, their effect on the distribution of [11C]-verapamil into the brain. 4. In vitro-vivo correlation: We will determine (a) if the above in vitro EC50 and in vivo ECso values in the rat are correlated; and (b) whether the in vitro and in vivo rodent data are predictive of the magnitude of interaction observed at the human BBB at the Cmax of the inhibitor. 5. P-QD allosterism and multiple binding sites: We will determine if the interaction of P-gp with its drug substrates demonstrates allosterism and multiple binding sites. If it does, these phenomena will need to be taken into consideration when predicting in vivo P-gp based drug interactions.

啮齿动物血脑屏障（BBB）的P-糖蛋白（P-GP； MDR1）的遗传敲除 P-gp底物药物在大脑中的分布显着增加（增加10至30倍）。基于 这些数据已被广泛假定，P-gp在限制人类药物分布中起着至关重要的作用 BBB和人类BBB的基于P-gp的药物相互作用可能是深刻的。我们的假设 挑战这个良好的范式，并声称这种互动将是适度的，因为 潜在的P-gp抑制剂药物的治疗性血浆浓度将不足以深刻抑制PGP 在人类BBB。此外，我们假设可以定量这种药物相互作用 通过体外细胞模型和大鼠体内研究预测。我们实验室的小说发展 和创新的非侵入性，正电子发射断层扫描（PET）成像方法，用于测量P-gp活性 在人类的BBB将使我们能够检验这些假设。由于P-gp可以证明变构激活 和多个结合位点，基于P-gp的药物相互作用的预测可能会使这些相互作用变得复杂 现象。因此，我们的具体目标是： 1。体外研究：我们将确定多种药物（EC50）抑制P-gp外排的效力 表达MDR1基因或空载体（对照细胞）的LLCPK1细胞的Verapamil-Bodipy。 2。体内啮齿动物研究：对于所研究的药物（AIM 1），我们将确定治疗性的比率 最大血浆浓度（CMAX）和EC50（CMAX/ECSO）以及未结合的最大值 血浆浓度（CMAXU）和EC5O（CMAXU/EC5O）。对于那些有效的药物（n = 4） P-gp的抑制剂在其治疗浓度下（最高比率），我们将确定其体内EC50 在大鼠BBB上使用[3H] - verapamil作为P-gp底物。 体内人类研究：将测试从大鼠研究中发现的两个最有效的抑制剂（AT CMAX）通过测量PET测量其对人BBB抑制P-gp活性的能力 [11C] - verapamil在大脑中的分布。 4。体外 - 体内相关性：我们将确定（a）如果上述体外EC50和体内ECSO值 大鼠相关； （b）体外和体内啮齿动物数据是否可以预测 在抑制剂CMAX处观察到的相互作用的大小。 5。P-QD变构和多种结合位点：我们将确定P-gp与其药物的相互作用是否相互作用 底物证明了变构和多种结合位点。如果是这样，这些现象将需要 在预测基于体内P-gp的药物相互作用时要考虑。